The present invention relates to an adjustable anchorage for seat belts for the protection of vehicle occupants. The present invention finds application in what is known as a three-point seat belt system in which the seat belt and in particular the shoulder belt portion is looped through a D-ring or similar device which is often fixedly attached to the "B" pillar of a vehicle. The rigid attachment of the D-ring or anchorage to the vehicle does not provide flexibility in the operation of the seat belt system to accommodate varying sizes of the occupants. In a system employing a fixed anchorage, the anchor point is chosen to accommodate an occupant of average size. In this manner the shoulder belt is designed to contact the shoulder of the occupant and then extend diagonally across the occupant's torso to a buckle. This, however, is not the case with occupants who are taller or shorter than average. To accommodate for varying size of occupants, adjustable anchorage mechanisms have been proposed in the prior art, one of which is the commonly owned U.S. Pat. No. Re. 32,524. Other adjustable anchorage mechanisms can be found in U.S. Pat. No. 4,556,255 as well as in a variety of Great British patent applications such as 2,124,889; 2,132,071; 2,136,070 and 2,138,670.
It is an object of the present invention to provide a manually adjustable seat belt anchorage which is of simple construction and one which maintains its structural integrity and performance during high deceleration and vehicle crash situations.
Accordingly, the invention comprises: an adjustable seat belt anchorage comprising: a guide rail adapted to be secured to a portion of a vehicle generally at or above occupant shoulder height. The guide rail forms an open channel, and includes a plurality of pairs of cut-outs or slots oppositely positioned in front walls of the guide rail. The anchorage further includes a latch plate assembly comprising: a resilient carrier slidingly received within the channel; a latching mechanism biased into the guide rail by the carrier and supported by and movable within the carrier. The latching mechanism includes a latch bar extending upwardly from the carrier to engage a selected pair of cut-outs and an attachment means such as a threaded bushing or threaded stud for supporting a safety belt support device such as a D-ring. The latching mechanism is moved to engage a different set of cut-outs by depressing it and sliding it in the guide rail. Various springs are used to supplement the resiliency of the carrier. In one embodiment the spring is bifurcated. In another embodiment a flat spring is used having a bent end. A roller is inserted in the bent end which engages a curved end of the latch bar as a function of the degree to which the latching mechanism is depressed. The use of the roller and spring provide for a means of varying the force exerted on the latch bar. In another embodiment of the invention the roller and bent spring are replaced with a rolled spring.
Many other objects and purposes of the invention will be clear from the following detailed description of the drawings.